Process of producing compounds of rubber and steel-wool.



J. P. CRANE. PROCESS OF PRODUCING COMPOUNDS OF RUBBER AND STEEL WOOL.

. APPLICATION FILED MAR. 8. I91].

Patented Sept. 1915.

JAMES P. CRANE, 01?

Application filed March 18,

To all whom it may concern:

Be it known that I, JAMns P. CRANE, a

V citizen of the United States, and a resident of Chicago, in the countyof Cook and State of Illinois, have invented certain new and usefulImprovements in the Process of Producing Compounds of Rubber and Steel-Wool, of which the following is a full, clear, and exact specification.

. This invention relates to improvements in the process in reducing.compounds composed generally of rubber and analogous gums and steelwool, but particularly of compounds consisting of resilient vulcanizedrubber and steel wool, especially adapted to the construction ofautomobile and bicycle tires, shoe heels and soles,-hoof pads and otherarticles wherein resiliency and durability of the rubber are essentialand the non-slipping and non-skidding of their surfaces are desirableand important.

Steel wool is a well recognized article of commerce, every fiber ofwhich is threadlike and has an irregular and triangular shape, givingsteel wool a peculiar quality for rubbing and other purposes, andrequiring for its production specially manufac-' tured and prepared wireand expensive special machinery, tools and skilled labor, and is sodifferent in the material of which it is composed, manner of itsproduction,

form and appearance to the eye and touch,

and in its characteristics and uses for which it is adapted from leadwool or other fibers or turnings, that it is clearly distinguishablefrom and is not to be confused with same. r

Heretofore such compounds have been formed of rubber and steel wool,mixed together by vulcanizing under pressure, or by repeatedly passingthe steel wool, together with raw rubber compound in dough-like form,between the pressure rollers of machines commonly and generally employedfor mixing raw rubber compound with its fluxes and its compounds untilthe fibers of the steel wool are thoroughly incorporated with anduniformly distributed throughout the mass of rubber as nearly as may bewithout regard to the direction of the fibers therein or the form theymay have, with the result that in the finished product of the compound,after it has been vulcanized, the fibers frequently present themselvesin the 1 form of many loops through the wearing away of the rubber,which loops in present- Specification of Letters Patent.

CHICAGO, ILLINOIS.

PROCESSOR PRODUCING COMPOUNDS OF RUBBER AND STEEL-WOOL.

Patented Sept. 7, 1915.

1911. Serial No. 615,253.

ing their side surfaces are practically useless for non-slipping andnon-skidding pur-- ing slipping, skidding and the frictional wear of acompound of rubber and steel wool fibers in automobile and bicycletires, shoe heels, etc., and it is to the securing of these results thatmy invention is directed.

The object of my invention is a process by which it is possible andpractical to produce a compound of rubber, and especially resilientvulcanized rubber and steel wool,. in which compound the fibers of thesteel wool shall be disposed generally in a longitudinal direction sothat the ends of the fibers shall receive and resist frictional wear ofan opposing surface, andat the same time operate as a binder preventingthe mass from undue lateral expansion from forces opposing its claims. 4

In said drawing :-F1gure 1 lllustrates,

in vertical section, a machine such as is commonly used for mixingrubber and its compounds with fluxes therefor; and, Fig. 2 illustrates aperspective view of a block or sheet of rubber compound embodying myinvention.

The mixing machine above referred to consists of a pan 3, supported uponlegs 4,

and opposing standards 5, in and between which are suitable journaledrollers 6 and 7 which are hollow, as indicated at 8, heated by steamsupplied through their hollow journals 9 and 10 respectively, the upperroller bein vertically adjustable by means of the ban wheel 11 forvarying the thickness of the sheet or slab of the rubber compound passedbetween them, said upper roller being provided with a gear 12, and thelower roller by a larger gear 13,0011- nected by means of pinions 14 and15, wherein a bunched or massed condition. may be reduced to asheet-like form, subsequently interposed between raw or semi-curedrubber until the fibers are disposed longitudinally and generally inparallelism with each other and still retain a more or less kinked formand curled condition.

Asthe cheapest, quickest and most satisfactory means, however, I havefound that after mixing and uniformly distributing the fibers of thesteel wool with raw rubber in mixing machines commonly and generallyemployed for mixing raw rubber with its fluxes and its compounds, andthen passing the mixed mass between the pressure rollers thereof anumber of times in the same direction, and until the mass is reduced toa slab or sheet-like form for subsequent use, the fibers of the steelwool are disposed generally in a longitudinal direction withoutdestroying their curled and kinked form to a degree reducing theireffectiveness as a binder for and preventing the rubber of the finishedvulcanizing compound from objectionably spreading when used for thepurposes, above described.

The fibers of the steel wool, being cut as -they are from a steel wire,in order to produce long fine fibers of curled and kinked form, are, byreason of the cutting process, unavoidably so brittlethat they breakinto a number of pieces when subjectedto the pressure of a vulcanizingmold and to the pressure of rollers of mixing machines used in combiningthem with the rubber and distributing their fibers throughout a slab orsheet by the repeated roller pressure before described, with the resultthat the fibers of the steel wool are not nearly so effective either asa binder, as regards durability, the

reduction of the frictional wear of the rubber, or for reducing theslipping and skidding of automobile and bicycle tires, shoe heels, etc.

In carrying out my invention I, therefore, in practice preferably drawthe temper from the fibers of the steel wool, as may be, by anywell-known process of annealing until sufficient brittleness is removedfrom the fibers to enable them to substantially rekinked form forconstituting a binder for the rubber for all the practical purposes andresults before specified. After the fibers have been so annealed theymay be reduced to a sheet-like form and a general longitudinaldisposition by combing or other means, but in practice it is preferredto pass them, with rubber compound in a dough-like state, between therollers of an ordinary commonly used rubber mixing machine, and afterbe-.

ing thoroughly incorporated with the rubber, and the fibers distributedtherethrough as uniformly as may be, the mixed mass is then repeatedlypassed between the rollers in the same direction until the fibers extendin a general longitudinal direction substantially parallel with eachother, until there is finally produced a slab or sheet in which thefibers are so disposed and remain throughout the subsequent vulcanizingprocess.

The longitudinal disposal of the fibers of steel wool in a rubbercompound, such as above described, provide a means by which the steelwool in articles made therefrom may receive frictional wear upon itsends, and, therefore, on the surface of steel wool best resistingfrictional wear, reducing the wear of the rubber, maintaining the rubberfrom slipping and skidding on opposing surfaces, and preventing anyundue protrusion of the fibers from the surface of the rubber, wherebythe breaking off of the fibers is prevented, and also the rubber surfacewearing away from friction substantially faster than the wearing off ofthe fibers.

Having described my invention, what I claim and desire to secure byLetters Patent is k 1. The herein described method of producing a comound composed of resilient vulcanized ru ber and steel wool, the sameconsisting in first mixing rubber and steel wool in the usual manner,and then subjecting the compound to a force moving the fibers of thesteel wool to substantially longitudinal parallelism to each other, andfinally vulcanizing the compound with the fibers of steel wool in saidposition, substantially as described.

2. The herein described method of producing a compound composed ofresilient vulcanized rubber and steel wool, the same consisting inmixing rubber and steel wool until the steel wool is distributedthroughout the mass, and then subjecting the mixed mass to a forcemoving the fibers of the steel wool to substantially longitudinalparallelism with each other throughout the mass and msaess wool in saidposition, substantially as described. 1O

4. The herein described process for producing a compound composed ofrubber and steel wool fibers, which consists in drawing the temper ofthe fibers of steel wool to a degree preventing their undue breakingunder the pressure of their incorporation ing compounds of resilientvulcanized rubber and steel wool, the same consisting in drawing thetemper of the fibers thereof until an undue breaking brittleness underpressure is removed therefrom, then mixing said fibers with rubber indough-like form until distributed through a given mass of rubber asuniformly as may be, and then repeatedly drawing said mixed mass betweenpressure rollers a sufiicient number of times in the same direction toproduce the disposal of the metal fibers in the same generallongitudinal parallel direction throughout the mass.

In witness whereof, I have hereunto set my hand and affixed my seal,-this3rd day of March, A. D. 1911..

JAMES P. CRANE. [1,. s.] Witnesses: 7 r

Y F. E. BRoM,

. JOHN G. ELLIOTT.

